JP2022105940A - Lader processing device and laser processing method - Google Patents

Abstract

To improve production efficiency when pixels formed on a substrate are processed with laser light.SOLUTION: A laser processing device includes: a laser oscillator which emits laser light; a first branch element which is disposed on an optical path of the laser light and branches the optical path of the laser light into a first optical path and a second optical path different from the first optical path; a first laser optical system disposed on the first optical path; a second laser optical system disposed on the second optical path; a first stage on which a first workpiece to be processed by first laser light emitted from the first laser optical system is placed; a second stage on which a second workpiece to be processed by second laser light emitted from the second laser optical system is placed; and a stage control part which controls positions of the first stage and the second stage to control a radiation position of the first laser light to the first workpiece and a radiation position of the second laser light to the second workpiece.SELECTED DRAWING: Figure 1

Description

The present invention relates to a laser processing apparatus and a laser processing method.

In recent years, the development of a display device using a minute micro LED having a size of one LED of less than 1 mm (micron order) as a pixel has been progressing. The display device forms a semiconductor laminate including a light emitting semiconductor layer on a sapphire substrate, separates the semiconductor laminate at the boundary between the sapphire substrate and the semiconductor laminate, and then joins the separated semiconductor laminate to another support substrate. It is formed by.

In Patent Document 1, a laminate containing micro LEDs formed on one surface of a sapphire substrate mounted on a stage is irradiated with laser light by pulse oscillation from the other surface of the sapphire substrate, and each of them is irradiated with laser light. A processing method by laser lift-off that separates the micro LED from the sapphire substrate is described.

Japanese Unexamined Patent Publication No. 2019-83280

When manufacturing a micro LED display device, if the size of the sapphire substrate on which the micro LED is formed or the substrate on which the micro LED is transferred (carrier substrate, circuit board, etc.) is large, the area where laser light must be irradiated. It is necessary to move the stage because it also becomes large. At this time, if the moving time of the stage is longer than the frequency of the laser oscillation, the laser beam must be emitted after waiting for the moving of the stage to be completed, which reduces the production efficiency of the display device. Resulting in. Further, even if an alignment operation is required every time the stage is moved, the production efficiency of the display device is lowered.

In view of the above problems, one of the objects of the embodiment of the present invention is to improve the production efficiency when the pixels formed on the substrate are processed by the laser beam.

The laser processing apparatus according to the embodiment of the present invention is arranged on a laser oscillator that emits a laser beam and an optical path of the laser beam, and the optical path of the laser beam is different from the first optical path and the first optical path. From the first branching element that branches into two optical paths, the first laser optical system arranged on the first optical path, the second laser optical system arranged on the second optical path, and the first laser optical system. The first stage on which the first workpiece to be processed by the emitted first laser beam is placed and the second workpiece to be processed by the second laser beam emitted from the second laser optical system are mounted. Positions of the first stage and the second stage in order to control the second stage to be placed, the irradiation position of the first laser beam on the first workpiece, and the irradiation position of the second laser beam on the second workpiece. The stage control unit has a stage control unit, and the first branch element alternately switches between the first optical path and the second optical path, and the stage control unit is the first when the first optical path is selected. It controls the position of the two stages and controls the position of the first stage when the second optical path is selected.

In the laser processing method according to the embodiment of the present invention, a first optical path and a first optical path, which emits laser light from a first laser oscillator and is branched by a first branch element arranged on the optical path of the first laser oscillator. When the first optical path is selected from the second optical path different from the optical path of the above, the irradiation position of the first workpiece is irradiated with the first laser beam emitted from the first laser optical system. When the second optical path is selected, the second laser beam emitted from the second laser optical system is applied to the irradiation position of the second workpiece, and the first optical path and the second optical path are alternately switched. ..

It is a block diagram explaining the schematic structure of the laser processing apparatus which concerns on one Embodiment of this invention. It is a schematic diagram explaining the structure of a laser optical system. It is a top view of the work piece. It is sectional drawing of the workpiece. It is a figure explaining the operation method of the laser processing apparatus which concerns on one Embodiment of this invention. It is a figure explaining the operation method of the laser processing apparatus which concerns on one Embodiment of this invention. It is a timing chart explaining the operation of the manufacturing apparatus which concerns on one Embodiment of this invention. It is a block diagram explaining the schematic structure of the laser processing apparatus which concerns on one Embodiment of this invention. It is a schematic diagram explaining the structure of a laser optical system. It is a timing chart explaining the operation of the manufacturing apparatus which concerns on one Embodiment of this invention. It is a timing chart explaining the operation of the manufacturing apparatus which concerns on one Embodiment of this invention.

Hereinafter, embodiments of the present invention will be described with reference to the drawings and the like. However, the present invention can be implemented in many different embodiments and is not construed as being limited to the description of the embodiments exemplified below. Further, in order to clarify the explanation, the drawings may schematically represent the width, thickness, shape, etc. of each part as compared with the actual embodiment, but this is just an example, and the interpretation of the present invention is used. It is not limited. Further, in the present specification and each figure, the same elements as those described above with respect to the above-mentioned figures may be designated by the same reference numerals, and detailed description thereof may be omitted as appropriate.

<First Embodiment>
The configuration of the laser processing apparatus 100 according to the embodiment of the present invention and the driving method thereof will be described with reference to FIGS. 1 to 6.

<Outline configuration of manufacturing equipment>
FIG. 1 is a block diagram illustrating a schematic configuration of a laser processing apparatus 100 according to an embodiment of the present invention. The laser processing apparatus 100 includes a control unit 101, a laser oscillator 103, a branch element 105, laser optical systems 107_1 and 107_2, and stage control units 108_1 and 108_2. In addition, the laser processing apparatus 100 also has a laser control unit 102, a mirror 104, mirrors 106_1, 106_2, and stages 109_1, 109_2. In the following description, when the laser optical systems 107_1 and 107_2, the stage control units 108_1 and 108_2, and the stages 109_1 and 109_2 are not distinguished from each other, they are described as the laser optical system 107, the stage control unit 108, and the stage 109. The same applies to the components of the mirror 106 and the laser optical system 107.

The control unit 101 is connected to the laser control unit 102, the laser optical system 107, the branch element 105, and the stage control unit 108, and is each of the laser control unit 102, the laser optical system 107, the branch element 105, and the stage control unit 108. Controls the operation of.

By receiving the control signal from the control unit 101, the laser control unit 102 sets the laser output value and supplies power to the laser oscillator 103.

The laser oscillator 103 emits a laser beam 10 of a pulse generated by laser oscillation. The laser oscillator 103 can use, for example, an excimer laser or a UV solid-state laser, but is not particularly limited in one embodiment of the present invention. The laser oscillator 103 can be appropriately selected for an object and a purpose to be irradiated with the laser beam 10. For example, when the micro LED is laser lifted off, a picosecond pulse laser having a wavelength of 266 nm, which is a fourth harmonic (FHG: Fourth-Harmonic Generation), is used by a YAG laser oscillator in the solid UV (Ultra Violet) region. It is preferable to do so. Further, when the micro LED is lifted off, it is preferable to use a UV wavelength using an excimer laser. When joining a micro LED to a circuit board or the like, it is preferable to use an IR laser having a diameter of 900 nm to 1200 nm as a semiconductor laser.

The mirror 104 is arranged on the optical path of the laser beam 10 and changes the optical path of the laser beam 10. The mirror 104 reflects the laser beam 10 emitted from the laser oscillator 103 and changes the optical path toward the branch element 105.

The branching element 105 has a function of branching the optical path of the laser beam 10 into a first optical path and a second optical path different from the first optical path. In FIG. 1, the first optical path is along the first direction D1 and the second optical path is along the second direction D2. Further, as the branching element 105, for example, a beam splitter is used. The solid line laser beam 10 shown in FIG. 1 shows the first optical path branched by the branching element 105, and the dotted line laser beam 10 shows the second optical path branched by the branching element 105.

Further, although not shown in FIG. 1, the laser processing apparatus 100 has a shutter for selecting either the laser beam 10 of the first optical path or the laser beam 10 of the second optical path branched by the branching element 105. You may. The shutter may be provided between the branch element 105 and the laser optical system 107_1, and between the branch element 105 and the laser optical system 107_1. Further, the shutter may be provided between the branch element 105 and the laser optical system 107 between the branch element 105 and the mirrors 106_1 and 106_2, or between the mirrors 106_1 and 106_1 and the laser optical systems 107_1 and 107_2. It may be provided between them. Alternatively, the shutter may be provided inside the laser optical system 107_1 and the laser optical system 107_2, respectively. When the shutter is open, the laser beam 10 passes through, and when the shutter is closed, the laser beam 10 is blocked. For example, when the shutter provided between the branch element 105 and the laser optical system 107_1 is in the open state and the shutter provided between the branch element 105 and the laser optical system 107_1 is in the closed state, the first state is used. The laser beam 10 in the optical path is selected. Therefore, the position of the shutter is not particularly limited as long as it can select either the laser beam 10 of the first optical path or the laser beam 10 of the second optical path branched by the branching element 105.

Further, in one embodiment of the present invention, a switching element may be used instead of the branch element 105. The switching element has a function of switching the optical path of the laser beam 10 between the first optical path and the second optical path. For example, a mirror is used as the switching element. When a switching element is used instead of the branch element 105, the shutter described above may or may not be used.

The stage control unit 108_1 is connected to the control unit 101 and the stage 109_1, and the stage control unit 108_1 is connected to the control unit 101 and the stage 109_2. The stage control unit 108_1 controls the movement of the stage 109_1 for transporting and positioning the workpiece 200_1 according to the control signal output from the control unit 101. Similarly, the stage control unit 108_2 controls the movement of the stage 109_2 for transporting and positioning the workpiece 200_2 according to the control signal output from the control unit 101. In FIG. 1, an example in which each of the stages 109_1 and 109_2 is controlled by two stage control units 108_1 and 108_2 is shown, but one stage control unit 108 may control two stages 109_1 and 109_2, respectively. .. The stages 109_1 and 109_1 are, for example, XYθ stages that enable in-plane positioning control of the stage.

The mirror 106 further changes the first optical path or the second optical path of the laser beam 10 toward the laser optical system 107. The mirror 106_1 deflects the first optical path of the laser beam 10 emitted from the branching element 105 in the third direction D3. Further, the mirror 106_2 deflects the second optical path emitted from the branch element 105 in the third direction D3. The mirrors 104 and 106 may be arranged differently depending on the position where the branch element 105 is arranged, or may be omitted as appropriate.

The laser optical system 107_1 irradiates the workpiece 200_1 placed on the stage 109_1 with the laser beam 10. Similarly, the laser optical system 107_2 irradiates the workpiece 200_2 placed on the stage 109_2 with the laser beam 10. The configurations of the laser optical systems 107_1 and 107_2 will be described in detail with reference to FIG.

FIG. 2 is a perspective view illustrating the configuration of the laser optical systems 107_1 and 107_2. Mirrors 106_1 and 106_1 are provided in the vicinity of the laser optical systems 107_1 and 107_2. The laser optical system 107_1 has at least one of a galvano scanner 170_1 and a condenser lens 175_1. Similarly, the laser optical system 107_2 has at least one of a galvano scanner 170_2 and a condenser lens 175_2. FIG. 2 shows a configuration in which the laser optical system 107_1 has both a galvano scanner 170_1 and a condenser lens 175_1, and the laser optical system 107_1 has both a galvano scanner 170_2 and a condenser lens 175_1.

The galvano scanner 170_1 includes an X-scan mirror 171_1, an X-axis motor 172_1 that controls the X-scan mirror 171_1, a Y-scan mirror 173_1, and a Y-axis motor 174_1 that controls the Y-scan mirror 173_1. Similarly, the galvano scanner 170_2 has an X-scan mirror 171_2, an X-axis motor 172_2 that controls the X-scan mirror 171_2, a Y-scan mirror 173_2, and a Y-axis motor 174_2 that controls the Y-scan mirror 173_2. The X-axis motors 172_1 and 172_2 and the Y-axis motors 174_1 and 174_1 are controlled by the control unit 101. By scanning the X scan mirrors 171_1 and 172_2 in the X direction, the laser beam 10 can be scanned in the X direction. By scanning the Y scan mirrors 173_1 and 174_2 in the Y direction, the laser beam 10 can be scanned in the Y direction. By scanning the X scan mirrors 171_1 and 171_2 and the Y scan mirrors 173_1 and 173_2, the laser beam 10 can be irradiated to the entire irradiation area of the workpieces 200_1 and 200_1. Here, the irradiation area refers to a range in which the laser optical system 107 can irradiate the workpiece 200 with the laser beam 10 while the stage 109 is fixed. The irradiation area is, for example, a range of 100 mm ² , but the range of the irradiation area is not limited to this. Therefore, when the area of the workpiece 200 is large, there may be a plurality of irradiation areas in the workpiece 200. Further, a mask may be provided between the galvano scanner 170 and the workpiece 200, and the irradiation area may be determined by the mask.

The condenser lenses 175_1 and 175_2 are, for example, fθ lenses. The condenser lens 175_1 collects the laser beam 10 reflected by the Y scan mirror 173, and irradiates the surface of the workpiece 200_1 arranged on the stage 109_1 with the laser beam 10. Similarly, the condenser lens 175_2 collects the laser beam 10 reflected by the Y scan mirror 173_2, and irradiates the surface of the workpiece 200_2 arranged on the stage 109_2 with the laser beam 10.

<Workpiece>
Next, an example of the workpiece 200 in the present embodiment will be described with reference to FIGS. 3A and 3B.

FIG. 3A is a plan view showing an example of the workpiece 200 in the present embodiment. The workpiece 200 includes a plurality of micro LEDs 211 formed on one surface of the sapphire substrate 201. Here, the sapphire substrate 201 has a disk shape and may have a diameter of 2 to 8 inches. The disk shape may include a partially cut shape. The thickness of the sapphire substrate 201 is, for example, 0.2 mm. Further, the size of the micro LED 211 is, for example, 3 μm to 300 μm in length, width, and height, respectively. As an example, it is 20 μm (horizontal) × 20 μm (vertical) and has a height of 10 μm. As another example, it is 5 μm (horizontal) × 5 μm (vertical) and has a height of 3 μm.

FIG. 3B is a cross-sectional view of the workpiece 200 shown in FIG. 3A cut along the lines A1-A2. The workpiece 200 has a boundary portion 212 between the sapphire substrate 201 and the micro LED 211. The boundary portion 212 is a peeling layer for laser lift-off. The micro LED 211 can be separated from the sapphire substrate 201 at the boundary portion 212 by aligning the focal position of the laser beam with the boundary portion 212 from the other surface side of the sapphire substrate 201 and performing laser ablation. In the following description, the sapphire substrate 201 is arranged so that one surface on which the micro LED 211 is formed is on the stage 109 side and the other surface is on the laser optical system 107 side.

<Operation of manufacturing equipment>
Next, the operation of the laser processing apparatus 100 configured as described above will be described with reference to FIGS. 1, 4 to 6. FIG. 4 is a diagram showing a case where the first optical path is selected as the optical path of the laser beam 10 shown in FIG. 1, and FIG. 5 is a diagram showing a case where the second optical path is selected as the optical path of the laser beam 10 shown in FIG. It is a figure which shows the case which is done. Further, FIG. 6 is a timing chart illustrating the operation of the laser processing apparatus 100.

Here, the workpieces 200_1 and 200_1 have the micro LED 211 formed on the sapphire substrate 201. A method of separating the micro LED 211 from the sapphire substrate 201 by irradiating the sapphire substrate 201 with the laser beam 10 will be described. Further, the sapphire substrates 201_1 and 201_2 each have a plurality of irradiation areas.

At time T0, the workpiece 200_1 is set on the stage 109_1 of the laser machining apparatus 100 configured as shown in FIG. The workpiece 200_1 is arranged on the stage 109_1 so that the other surface of the sapphire substrate 201_1, that is, the surface on which the micro LED 211 is not formed is the upper surface. Similarly, the workpiece 200_2 is set on the stage 109_2. The workpiece 200_2 is arranged on the stage 109_2 so that the other surface of the sapphire substrate 201_2, that is, the surface on which the micro LED 211 is not formed is the upper surface.

At time T1, the condensing position of the condensing lens 175_1 is aligned with the boundary portion 212 of the workpiece 200_1 in the Z direction in the laser optical system 107_1 by the control signal received from the control unit 101. In response to the control signal from the control unit 101, the stage control unit 108_1 moves the stage 109_1 in the X direction and the Y direction to position the irradiation area 210_1. Next, in response to the control signal from the control unit 101, the galvano scanner 170_1 controls the X-axis motor 172_1 and the Y-axis motor 174_1 to control the X-scan mirror 171_1 and the Y-scan mirror 173_1. As a result, the position where the laser beam 10 is first irradiated on the workpiece 200_1 is determined. The irradiation area 210_1 is a predetermined area based on the position where the laser beam 10 is first irradiated.

When the positioning of the stage 109_1 and the laser optical system 107_1 is completed at the time T2, the laser beam 10 is emitted from the laser oscillator 103. The emitted laser beam 10 is reflected by the mirror 104 and branched into a first optical path and a second optical path by the branching element 105. Here, the laser beam 10 in the second optical path is blocked by the shutter in the closed state. The laser beam 10 in the first optical path passes through the shutter in the open state and is reflected by the mirror 106_1. Then, as shown in FIG. 4, the laser beam 10 reflected by the mirror 106_1 is incident on the laser optical system 107_1. The laser optical system 107_1 deflects the laser beam 10 by the X scan mirror 171_1 and the Y scan mirror 173_1, and condenses the laser light 10 on the workpiece 200_1 by the condenser lens 175_1.

In the workpiece 200_1, when the boundary portion 212 between the sapphire substrate 201 and the micro LED 211 is irradiated with the laser beam 10, the micro LED 211 can be separated from the sapphire substrate 201 at the boundary portion 212.

After that, the laser optical system 107_1 irradiates the irradiation area 210_1 while moving the laser beam 10 in the X direction and the Y direction. When a plurality of micro LEDs 211 are arranged vertically and horizontally in the irradiation area 210_1, for example, 20 horizontally and 20 vertically, all of these micro LEDs 211 are irradiated with the laser beam 10 to make micro. Separate the LED 211. As a result, the plurality of micro LEDs 211 arranged in the irradiation area 210_1 can be separated from the sapphire substrate 201. When all the micro LEDs 211 in the irradiation area 210_1 are separated from the sapphire substrate 201, the control unit 101 stops the irradiation of the laser light from the laser optical system 107_1.

At time T2, the control unit 101 positions the laser optical system 107_2 and the stage 109_2 while the laser optical system 107_1 separates the plurality of micro LEDs 211 arranged in the irradiation area 210_1 from the sapphire substrate 201. ..

By the control signal received from the control unit 101, in the laser optical system 107_2, the focusing position of the condenser lens 175_2 is aligned with the boundary portion 212 of the workpiece 200_2 in the Z direction in the same manner as in the laser optical system 107_1. In response to the control signal from the control unit 101, the stage control unit 108_2 moves the stage 109_2 in the X direction and the Y direction to position the irradiation area 220_1. Next, in response to the control signal from the control unit 101, the galvano scanner 170_2 controls the X-axis motor 172_2 and the Y-axis motor 174_2 to control the X-scan mirror 171_2 and the Y-scan mirror 173_2. As a result, the position where the laser beam 10 is first irradiated on the workpiece 200_2 is determined. The irradiation area 220_1 is a predetermined area based on the position where the laser beam 10 is first irradiated.

At time T3, the optical path of the laser beam 10 is switched from the first optical path to the second optical path. Here, the laser beam 10 in the first optical path is blocked by the shutter in the closed state. The laser beam 10 in the second optical path travels straight toward the mirror 106_2 and is further reflected by the mirror 106_2. Then, as shown in FIG. 5, the laser beam 10 reflected by the mirror 106_2 is incident on the laser optical system 107_2. The laser optical system 107_2 deflects the laser beam 10 by the X scan mirror 171_2 and the Y scan mirror 173_2, and condenses the laser light 10 on the workpiece 200_2 by the condenser lens 175_2.

At time T2, the positioning of the laser optical system 107_2 and the stage 109_2 is completed while the laser optical system 107_1 separates the plurality of micro LEDs 211 arranged in the irradiation area 210 from the sapphire substrate 201. In this case, it is preferable because the optical path of the laser beam 10 can be selected immediately. On the other hand, when the laser optical system 107_1 has not completed the positioning of the laser optical system 107_2 and the stage 109_2 while the plurality of micro LEDs 211 arranged in the irradiation area 210 are separated from the sapphire substrate 201. May temporarily stop the emission of the laser beam 10 from the laser oscillator 103. In this case, when the positioning of the laser optical system 107_2 and the stage 109_2 is completed, the optical path of the laser beam 10 may be switched from the first optical path to the second optical path, and the laser beam may be emitted from the laser oscillator again.

The laser optical system 107_2 irradiates the irradiation area 220_1 while moving the laser beam 10 in the X direction and the Y direction. When a plurality of micro LEDs 211 are arranged vertically and horizontally in the irradiation area 220_1, all of these micro LEDs 211 are irradiated with the laser beam 10 to separate the micro LEDs 211. As a result, all of the plurality of micro LEDs 211 arranged in the irradiation area 220_1 can be separated from the sapphire substrate 201. When all the micro LEDs 211 in the irradiation area 220_1 are separated from the sapphire substrate 201, the control unit 101 stops the irradiation of the laser light from the laser optical system 107_2.

At time T3, the control unit 101 refers to the irradiation area 210_1 adjacent to the irradiation area 210_1 while the laser optical system 107_2 separates the plurality of LEDs 211 arranged in the irradiation area 220_1 from the sapphire substrate 201. Positioning of the laser optical system 107_1 and the stage 109_1 is performed. In FIG. 5, the irradiation area 210_1 is shown as an irradiation area adjacent to the irradiation area 210_1 in the X direction, but may be an irradiation area adjacent to the Y direction.

In FIG. 6, the description of the time T2 may be referred to for the operation at the time T4 and the time T6, and the description of the time T3 may be referred to for the operation at the time T5. After the time T4, the laser processing apparatus 100 irradiates the laser beam 10 on all of the plurality of irradiation areas 210 of the workpiece 200_1 and all of the plurality of irradiation areas 220 of the workpiece 200_1 to form a sapphire substrate. The above operation is repeated until all the micro LEDs 211 formed in the above are separated.

According to the laser processing apparatus 100 according to the embodiment of the present invention, since the laser processing apparatus 100 has a plurality of laser optical systems 107_1 and 107_2, while the workpiece 200 corresponding to one of the laser optical systems is irradiated with the laser beam. The stage 109 can be moved to a position where the workpiece 200 corresponding to the other laser optical system is arranged. After that, when the irradiation of the laser beam 10 into the irradiation area of the workpiece 200 corresponding to the one laser optical system 107 is completed, the direction in which the laser beam 10 travels is changed to correspond to the other laser optical system 107. The irradiation of the laser beam 10 into the irradiation area of the workpiece 200 to be processed is started. While the work piece 200 corresponding to the other laser optical system 107 is irradiated with the laser beam 10, the stage 109 can be moved to the irradiation area of the work piece 200 corresponding to the other laser optical system 107. .. This makes it possible to improve the production efficiency required when processing pixels formed on a large-area substrate with laser light.

As described above, the laser processing apparatus 100 according to the embodiment of the present invention can alternately irradiate the lasers in the irradiation areas 210_1, 220_1, 210_2 of the two workpieces 200_1 and 200_1. The tact time can be reduced. Further, it is possible to process a plurality of workpieces 200_1 and 200_1 at almost the same time. Further, a plurality of workpieces 200_1 and 200_1 can be processed for one laser oscillator 103. As a result, the equipment cost can be significantly reduced as compared with the case where the number of laser oscillators 103 is increased.

In the present embodiment, the case where two laser optical systems 107_1 and 107_2 and stages 109_1 and 109_2 are used for one laser oscillator 103 has been described, but the embodiment of the present invention is not limited thereto. Three or more laser optical systems 107 and three or more stages 109 may be used for one laser oscillator 103. When three laser optical systems are used, for example, the laser beam branched by the branching element 105 is further divided into two by using a branching element. Then, each of the divided laser beams is incident on the two laser optical systems 107. At this time, it is preferable that the above-mentioned two laser optical systems 107 operate in the same manner. Further, it is preferable that the above-mentioned two laser optical systems 107 are alternately operated with the laser optical system 107 to which the laser light 10 reflected from the branch element 105 in the second state is incident.

Further, in the present embodiment, the case where the laser processing apparatus 100 is applied to the step of separating the micro LED 211 formed on the sapphire substrate 201 by the laser beam has been described, but the embodiment of the present invention is not limited to this. For example, in the manufacturing process of the micro LED display device, it may be applied to the step of joining the micro LED to the circuit board on which the transistor is formed. Specifically, the laser processing apparatus 100 is applied to a process in which a separated micro LED is mounted on a circuit board on which a transistor is formed, and the terminal of the micro LED and the terminal of the transistor are joined by laser light. You may.

<Second Embodiment>
The configuration of the laser processing apparatus 100A according to the embodiment of the present invention and the driving method thereof will be described with reference to FIGS. 7 to 10. In the following description, the same parts as those of the laser processing apparatus 100 or the parts having the same functions are designated by the same reference numerals, and the repeated description will be omitted.

<Outline configuration of manufacturing equipment>
FIG. 7 is a block diagram illustrating a schematic configuration of a laser processing apparatus 100A according to an embodiment of the present invention. The laser processing apparatus 100A includes a control unit 101, laser oscillators 103_1 and 103_2, branch elements 105_1 and 105_2, laser optical systems 107_1 to 107_1, and a stage control unit 108_1 to 108_4. In addition, the laser processing apparatus 100A has laser control units 102_1 and 102_2, mirrors 104_1 and 104_2, mirrors 106_1 to 106_1, and stages 109_1 to 109_1. Regarding the components of the laser processing apparatus 100A, the laser oscillator 103_1, the branch element 105_1, the laser control unit 102_1, the mirror 104_1, the mirror 106_1, and 106_1 are the laser oscillator 103, the branch element 105, and the laser described in the first embodiment. This is the same as the control unit 102, the mirror 104, and the mirror 106.

By receiving the control signal from the control unit 101, the laser control unit 102_2 sets the laser output value and supplies power to the laser oscillator 103_2.

The laser oscillator 103_2 emits the laser beam 20 of the pulse generated by the laser oscillation. The laser oscillator 103_2 can use, for example, an excimer laser or a UV solid-state laser, but is not particularly limited in one embodiment of the present invention. The laser oscillator 103_2 can be appropriately selected for an object and a purpose to be irradiated with the laser beam 20. For example, when the micro LED is laser lifted off, for example, a picosecond pulse laser having a wavelength of 266 nm, which is a fourth harmonic (FHG: Fourth-Harmonic Generation), is used by a YAG laser oscillator in the solid UV (Ultra Violet) region. It is preferable to use. Further, when the micro LED is lifted off, it is preferable to use a UV wavelength using an excimer laser. When joining a micro LED to a circuit board or the like, it is preferable to use an IR laser having a diameter of 900 nm to 1200 nm as a semiconductor laser. In the present embodiment, it is preferable to use the same laser light source as the laser oscillators 103_1 and 103_2 in order to lift off the laser to the workpieces 200_1 to 200_1.

The mirror 104_2 is arranged on the optical path of the laser beam 10 and changes the optical path of the laser beam 20. The mirror 104_2 reflects the laser beam 20 emitted from the laser oscillator 103_2 and changes the optical path toward the branch element 105_2.

The branching element 105_2 has a function of branching the optical path of the laser beam 20 into a third optical path and a fourth optical path different from the third optical path. In FIG. 7, the third optical path is along the second direction D2, and the fourth optical path is along the first direction D1. Further, as the branching element 105_2, for example, a beam splitter is used. The solid line laser beam 20 shown in FIG. 7 shows the third optical path branched by the branching element 105_2, and the dotted line laser beam 20 shows the fourth optical path branched by the branching element 105_2.

Further, although not shown in FIG. 7, the laser processing apparatus 100A has a shutter for selecting either the laser beam 20 of the third optical path or the laser beam 20 of the fourth optical path branched by the branching element 105_2. You may. The shutter may be provided between the branch element 105_2 and the laser optical system 107_3, and between the branch element 105_2 and the laser optical system 107_4. Further, the shutter may be provided between the branch element 105_2 and the laser optical system 107_4 between the branch element 105_2 and the mirrors 106_3 and 106_4, or may be provided between the mirror 106_3 and the mirror 104_4 and the laser optical systems 107_3 and 107_4. It may be provided between. Alternatively, the shutter may be provided inside the laser optical system 107_3 and the laser optical system 107_4, respectively. When the shutter is open, the laser beam 20 passes through, and when the shutter is closed, the laser beam 20 is blocked. For example, when the shutter provided between the branch element 105_2 and the laser optical system 107_3 is in the open state and the shutter provided between the branch element 105_2 and the laser optical system 107_4 is in the closed state, the third The laser beam 20 in the optical path is selected. The position of the shutter is not particularly limited as long as it can select either the laser beam 20 of the third optical path or the laser beam 20 of the fourth optical path branched by the branching element 105_2.

Further, in one embodiment of the present invention, a switching element may be used instead of the branch element 105_2. The switching element has a function of switching the optical path of the laser beam 20 between the third optical path and the fourth optical path. For example, a mirror is used as the switching element. When a switching element is used instead of the branch element 105_2, the shutter described above may not be used.

The stage control unit 108_3 is connected to the control unit 101 and the stage 109_3, and the stage 109_3 is connected to the control unit 101 and the stage 109_3. The stage control unit 108_3 controls the movement of the stage 109_3 that conveys and positions the workpiece 200_3 in response to the control signal output from the control unit 101. Similarly, the stage control unit 108_4 controls the movement of the stage 109_4 for transporting and positioning the workpiece 200_4 in response to the control signal output from the control unit 101. FIG. 7 shows an example in which each of the stages 109_1 to 109_4 is controlled by four stage control units 108_1 to 108_4, but one stage control unit 108 may control stages 109_1 to 109_1. The stages 109_3 and 109_4 are, for example, XYθ stages that enable in-plane positioning control of the stage.

The mirror 106_3 causes the third optical path of the laser beam 20 to be changed to the third direction D3 so as to be directed toward the laser optical system 107_3. Further, the mirror 106_4 causes the fourth optical path of the laser beam 20 to be changed to the third direction D3 so as to be directed toward the laser optical system 107_4. The mirrors 104_2, 106_3, and 106_4 may be arranged differently depending on the position where the branch element 105_2 is arranged, or may be omitted as appropriate.

The laser optical system 107_3 irradiates the workpiece 200_3 placed on the stage 109_3 with the laser beam 20. Similarly, the laser optical system 107_4 irradiates the workpiece 200_4 placed on the stage 109_4 with the laser beam 20. The configurations of the laser optical systems 107_3 and 107_4 are as shown in FIG.

FIG. 8 is a perspective view illustrating the configuration of the laser optical systems 107_3 and 107_4. The laser optical system 107_3 has at least one of a galvano scanner 170_3 and a condenser lens 175_3. Similarly, the laser optical system 107_4 has at least one of a galvano scanner 170_4 and a condenser lens 175_4. FIG. 8 shows a configuration in which the laser optical system 107_3 has both a galvano scanner 170_3 and a condenser lens 175_3, and the laser optical system 107_4 has both a galvano scanner 170_4 and a condenser lens 175_4. For the configurations of the laser optical systems 107_3 and 107_4, the description of the configurations of the laser optical systems 107_1 and 107_2 shown in FIG. 2 may be referred to.

<Operation of manufacturing equipment>
Next, the operation of the laser processing apparatus 100 configured as described above will be described with reference to FIGS. 7 to 9. FIG. 9 is a timing chart illustrating the operation of the laser processing apparatus 100. In the present embodiment, a method will be described in which the control unit 101 simultaneously controls the stages 109_1 and 109_3 and the laser optical systems 107_1 and 107_3, and simultaneously controls the stages 109_2 and 109_4 and the laser optical systems 107_2 and 107_4. Since the operations of the stages 109_1 and 109_2 and the laser optical systems 107_1 and 107_2 are the same as those of the timing chart shown in FIG. 6, the description thereof will be omitted as appropriate.

Here, the workpieces 200_3 and 200_4 have the micro LED 211 formed on the sapphire substrate 201. A method of separating the micro LED 211 from the sapphire substrate 201 by irradiating the sapphire substrate 201 with the laser beam 10 will be described. Further, each of the sapphire substrates 201_3 and 201_4 has a plurality of irradiation areas.

At time T0, the workpiece 200_3 is set on the stage 109_3 of the laser machining apparatus 100A configured as shown in FIG. 7. The workpiece 200_3 is arranged on the stage 109_3 so that the other surface of the sapphire substrate 201_3, that is, the surface on which the micro LED 211 is not formed is the upper surface. Similarly, the workpiece 200_4 is set on the stage 109_4. The workpiece 200_4 is arranged on the stage 109_4 so that the other surface of the sapphire substrate 201_4, that is, the surface on which the micro LED 211 is not formed is the upper surface.

At time T1, the condensing position of the condensing lens 175_3 is aligned with the boundary portion 212 of the workpiece 200_3 in the Z direction in the laser optical system 107_3 by the control signal received from the control unit 101. In response to the control signal from the control unit 101, the stage control unit 108_3 moves the stage 109_3 in the X direction and the Y direction to position the irradiation area 230_1. Next, in response to the control signal from the control unit 101, the galvano scanner 170_3 controls the X-axis motor 172_3 and the Y-axis motor 174_3 to control the X-scan mirror 171_3 and the Y-scan mirror 173_3. As a result, the position where the laser beam 20 is first applied to the workpiece 200_3 is determined. The irradiation area 230_1 is a predetermined area based on the position where the laser beam 20 is first irradiated.

When the positioning of the stage 109_3 and the laser optical system 107_3 is completed at the time T2, the laser beam 20 is emitted from the laser oscillator 103_2. The emitted laser beam 20 is reflected by the mirror 104_2 and branched into a third optical path and a fourth optical path by the branching element 105_2. Here, the laser beam 20 in the fourth optical path is blocked by the shutter in the closed state. The laser beam 20 in the third optical path passes through the shutter in the open state and is reflected by the mirror 106_3. Then, the laser beam 20 reflected by the mirror 106_3 is incident on the laser optical system 107_3. The laser optical system 107_3 deflects the laser beam 20 by the X scan mirror 171_3 and the Y scan mirror 173_3, and condenses the laser light 20 on the workpiece 200_3 by the condensing lens 175_3.

In the workpiece 200_3, when the boundary portion 212 between the sapphire substrate 201 and the micro LED 211 is irradiated with the laser beam 20, the micro LED 211 can be separated from the sapphire substrate 201.

After that, the laser optical system 107_3 irradiates the irradiation area 230_1 while moving the laser beam 20 in the X direction and the Y direction. When a plurality of micro LEDs 211 are arranged vertically and horizontally in the irradiation area 230_1, all of these micro LEDs 211 are irradiated with laser light 20 to separate the micro LEDs 211. As a result, the plurality of micro LEDs 211 arranged in the irradiation area 230_1 can be separated from the sapphire substrate 201. When all the micro LEDs 211 in the irradiation area 230_1 are separated from the sapphire substrate 201, the control unit 101 stops the irradiation of the laser light from the laser light 20 of the laser optical system 107_3.

At time T2, the control unit 101 positions the laser optical system 107_4 and the stage 109_4 while the laser optical system 107_3 separates the plurality of micro LEDs 211 arranged in the irradiation area 230_1 from the sapphire substrate 201. ..

By the control signal received from the control unit 101, in the laser optical system 107_4, the condensing position of the condensing lens 175_2 is aligned with the boundary portion 212 of the workpiece 200_4 in the Z direction in the same manner as in the laser optical system 107_3. In response to the control signal from the control unit 101, the stage control unit 108_4 moves the stage 109_4 in the X direction and the Y direction to position the irradiation area 240_1. Next, in response to the control signal from the control unit 101, the galvano scanner 170_4 controls the X-axis motor 172_4 and the Y-axis motor 174_4 to control the X-scan mirror 171_4 and the Y-scan mirror 173_4. Thereby, the position where the laser beam 20 is first irradiated to the workpiece 200_4 is determined. The irradiation area 240_1 is a predetermined area based on the position where the laser beam 20 is first irradiated.

At time T3, the optical path of the laser beam 20 is switched from the third optical path to the fourth optical path. Here, the laser beam 20 in the third optical path is blocked by the shutter in the closed state. The laser beam 20 in the fourth optical path travels straight toward the mirror 106_4 and is further reflected by the mirror 106_4. Therefore, the laser beam 20 reflected by the mirror 106_4 is incident on the laser optical system 107_4. The laser optical system 107_4 deflects the laser beam 20 by the X scan mirror 171_4 and the Y scan mirror 173_4, and condenses the laser light 20 on the workpiece 200_4 by the condensing lens 175_4.

The laser optical system 107_4 irradiates the irradiation area 240_1 while moving the laser beam 10 in the X direction and the Y direction. When a plurality of micro LEDs 211 are arranged vertically and horizontally in the irradiation area 240_1, all of these micro LEDs 211 are irradiated with the laser beam 10 to separate the micro LEDs 211. As a result, all of the plurality of micro LEDs 211 arranged in the irradiation area 240_1 can be separated from the sapphire substrate 201. When all the micro LEDs 211 in the irradiation area 240_1 are separated from the sapphire substrate 201, the control unit 101 stops the irradiation of the laser light from the laser optical system 107_4.

At time T3, the control unit 101 refers to the irradiation area 230_1 adjacent to the irradiation area 230_1 while the laser optical system 107_4 separates the plurality of LEDs 211 arranged in the irradiation area 240_1 from the sapphire substrate 201. Positioning of the laser optical system 107_3 and stage 109_3 is performed. Although the irradiation area 230_2 shows the case where it is an irradiation area adjacent to the irradiation area 230_1 in the X direction, it may be an irradiation area adjacent to the Y direction.

In FIG. 9, the description of the time T2 may be referred to for the operation at the time T4 and the time T6, and the description of the time T3 may be referred to for the operation at the time T5. After the time T4, the laser processing apparatus 100A irradiates all of the plurality of irradiation areas 230 of the workpiece 200_3 and all of the irradiation areas 240 of the workpiece 200_4 with the laser beam 20 to form the sapphire substrate. The above operation is repeated until all the micro LEDs 211 are separated.

According to the laser processing apparatus 100A according to the embodiment of the present invention, there are two laser oscillators 103_1 and 103_2, and a plurality of laser optical systems 107 can be synchronized with each of the laser oscillators 103_1 and 103_2. .. As a result, the laser processing device 100A can increase the number of workpieces 200 that can be processed at one time, so that the production efficiency of the display device is improved.

In the present embodiment, a method of simultaneously controlling the stages 109_1 and 109_3 and the laser optical systems 107_1 and 107_3 and simultaneously controlling the stages 109_2 and 109_4 and the laser optical systems 107_2 and 107_4 has been described. However, one embodiment of the present invention has been described. Is not limited to this. The stages 109_1 and 109_4 and the laser optical systems 107_1 and 107_4 may be controlled at the same time, and the stages 109_2 and 109_3 and the laser optical systems 107_1 and 107_3 may be controlled at the same time.

Further, the control unit 101 may alternately control the stage 109_1 and the stage 109_2, and alternately control the stage 109_3 and the stage 109_4, and the laser optical systems 107_1 and 107_2 and the laser optical systems 107_3 and 107_4 may be controlled alternately. There is no need to synchronize and control. That is, the laser optical systems 107_1 and 107_2 and the laser optical systems 107_3 and 107_4 may be controlled at different timings.

FIG. 10 is a timing chart illustrating the operation of the laser processing apparatus 100A. As shown in FIG. 10, the timing at which the laser beam 10 is switched between the first optical path and the second optical path and the timing at which the laser beam 20 is switched between the third optical path and the fourth optical path are different. There is. Specifically, the laser beam 10 is switched from the first optical path to the second optical path at time t5, while the laser beam 20 is switched from the third optical path to the fourth optical path at time t6. Be done. As described above, the laser optical systems 107_1 and 107_2 and the laser optical systems 107_3 and 107_4 do not have to operate in synchronization with each other, or may operate independently.

In the present embodiment, the laser lift-off is performed on the workpieces 200_1 to 200_1, but the embodiment of the present invention is not limited to this. The workpieces 200_1 and 200_1 may be subjected to laser lift-off, and the workpieces 200_1 and 200_1 may be subjected to processing other than laser lift-off. In this case, the light source of the laser oscillator 103_2 and the light source of the laser oscillator 103_1 may be different depending on the purpose of processing the workpieces 200_1 to 200_1. For example, when the micro LED is lifted off from the workpieces 200_1 and 200_2, an excimer laser may be used as the laser oscillators 103_1 and 103_2. Further, when the micro LED is bonded to the circuit board or the like with respect to the workpieces 200_3 and 200_4, a semiconductor laser may be used. In this case, the laser optical systems 107_1 to 107_4 and the stages 109_1 to 109_4 may be operated by the timing chart shown in FIG. 9 or may be operated by the timing chart shown in FIG.

Based on the laser processing apparatus described as the embodiment and the embodiment of the present invention, those skilled in the art have appropriately added, deleted, or changed the design of components, or added, omitted, or changed the conditions. Those are also included in the scope of the present invention as long as they have the gist of the present invention. Further, the above-described embodiments can be combined with each other as long as technical inconsistencies do not occur.

In addition, even if the action / effect is different from the action / effect brought about by the above-described embodiment, those that are clear from the description of the present specification or those that can be easily predicted by those skilled in the art are of course. Is understood to be brought about by the present invention.

In the scope of the present invention, those skilled in the art can correspond to various modified examples and modified examples, and it is understood that these modified examples and modified examples also belong to the scope of the present invention. For example, a person skilled in the art appropriately adds, deletes, or changes the design of each of the above-described embodiments, or adds, omits, or changes the conditions of the process, which is the gist of the present invention. Is included in the scope of the present invention as long as it is provided.

10, 20: Laser light, 100, 100A: Laser processing device, 101: Control unit, 102: Laser control unit, 103: Laser oscillator, 104: Mirror, 105: Branch element, 106: Mirror, 107: Laser optical system, 108: Stage control unit, 109: Stage, 170: Galvano scanner, 171: X scan mirror, 172: X axis motor, 173: Y scan mirror, 174: Y axis motor, 175: Condensing lens, 200: Work piece , 201: sapphire substrate, 210: irradiation area, 211: micro LED, 212: boundary, 220: irradiation area, 230: irradiation area, 240: irradiation area

Claims (14)

A laser oscillator that emits laser light and
A first branching element arranged on the optical path of the laser beam and branching the optical path of the laser beam into a first optical path and a second optical path different from the first optical path.
With the first laser optical system arranged on the first optical path,
With the second laser optical system arranged on the second optical path,
A first stage on which a first workpiece to be machined by the first laser beam emitted from the first laser optical system is placed, and
A second stage on which a second workpiece to be machined by the second laser beam emitted from the second laser optical system is placed, and
The positions of the first stage and the second stage are controlled in order to control the irradiation position of the first laser beam on the first workpiece and the irradiation position of the second laser beam on the second workpiece. Has a stage control unit and
The first branch element alternately switches between the first optical path and the second optical path.
The stage control unit controls the position of the second stage when the first optical path is selected, and controls the position of the first stage when the second optical path is selected.
Laser processing equipment. The laser processing apparatus according to claim 1, wherein the first laser optical system includes at least one of a first galvano scanner and a first condenser lens. The laser processing apparatus according to claim 1, wherein the second laser optical system includes at least one of a second galvano scanner and a second condenser lens. The laser processing apparatus according to claim 1, wherein the first branch element is a beam splitter. Instead of the first branch element, a first switching element is used.
The laser processing apparatus according to claim 1, wherein the first switching element switches the optical path of the laser beam between the first optical path and the second optical path. A laser oscillator that emits laser light and
A second branching element arranged on the optical path of the laser beam and branching the optical path of the laser beam into a third optical path and a fourth optical path different from the third optical path.
With the third laser optical system arranged on the third optical path,
With the fourth laser optical system arranged on the fourth optical path,
A third stage on which a third workpiece processed by the third laser beam emitted from the third laser optical system is placed, and
It has a fourth stage on which a fourth workpiece to be machined by the fourth laser beam emitted from the fourth laser optical system is placed.
The stage control unit has the third stage and the first stage in order to control the irradiation position of the third laser beam on the third workpiece and the irradiation position of the fourth laser beam on the fourth workpiece. Control the position of 4 stages,
The second branch element alternately switches between the first optical path and the third optical path.
The stage control unit controls the position of the fourth stage when the third optical path is selected, and controls the position of the third stage when the fourth optical path is selected. The laser processing apparatus according to 1. A second switching element is used instead of the second branch element.
The laser processing apparatus according to claim 6, wherein the second switching element switches the optical path of the laser beam between the first optical path and the second optical path. Laser light is emitted from the first laser oscillator,
The first optical path is selected from the first optical path branched by the first branch element arranged on the optical path of the first laser oscillator and the second optical path different from the first optical path. At this time, the first laser beam emitted from the first laser optical system is applied to the irradiation position of the first workpiece to be irradiated.
When the second optical path is selected, the irradiation position of the second processed object is irradiated with the second laser beam emitted from the second laser optical system.
A laser processing method in which the first optical path and the second optical path are alternately switched. The laser processing method according to claim 8, wherein the first laser optical system includes at least one of a first galvano scanner and a first condenser lens. The laser processing method according to claim 8, wherein the second laser optical system includes at least one of a second galvano scanner and a second condenser lens. The laser processing method according to claim 8, wherein the first branch element is a beam splitter. Instead of the first branch element, a first switching element is used.
The laser processing method according to claim 8, wherein the first switching element switches the optical path of the laser beam between the first optical path and the second optical path. Laser light is emitted from the second laser oscillator,
The third optical path is selected from the third optical path branched by the second branch element arranged on the optical path of the second laser oscillator and the fourth optical path different from the third optical path. At this time, the third laser beam emitted from the third laser optical system is applied to the irradiation position of the third workpiece to be irradiated.
When the fourth optical path is selected, the fourth laser beam emitted from the fourth laser optical system is applied to the irradiation position of the fourth work piece.
The laser processing method according to claim 8, wherein the third optical path and the fourth optical path are alternately switched. A second switching element is used instead of the second branch element.
The laser processing method according to claim 13, wherein the second switching element switches the optical path of the laser beam between the third optical path and the fourth optical path.

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